Lumbar back rest



FIG. 1 is a front perspective view of the lumbar back rest.

FIG. 2 is a rear perspective view of the lumbar back rest.

FIG. 3 is a top view of the lumbar back rest.

FIG. 4 is a front elevational view of the lumbar back rest.

FIG. 5 is a side elevational view of the lumbar back rest.

FIG. 6 is a rear elevational view of the lumbar back rest; and,

FIG. 7 is a bottom view of the lumbar back rest.

The ornamental design for a lumbar back rest, as shown and described.